Yes, I am sure.  They showed me the bank statements for 12 months of 2021.  And there was NONE.

And as I said initially, they didn't need to file return for the years of 2019 and 2020.  Even before that, they never used their bank account for tax.

And I asked them if they received an envelope for Debit card for EIP payment, and they told me NO.

I am not worried about EIP3, and even if their memory lapsed and didn't remember their receipt of the debit card in lieu of Direct Deposit, I am sure that the IRS simply adjusted the RRC amount to "zero" and send a letter to  them, advising that the IRS records showed that the EIP has been paid to them, or something like that.

I simply need to be mindful of the implication of 1099-B.

The first requirement of the gross income over $27,800 is met.

The second requirement about 1099-B has to be met.

Yet, the return's bottom line is Tax amount ZERO.

That's how I got perplexed, but I got an answer from somebody, who asked me to check the tax rate.
From the worksheet, I found that the rate of "0"% was applied.

Gross income - Standard deduction = $25K.

Capital gains are more than $35K.

Qualified dividends are about $300.

The tax rate is determined to be "zero"

What I am not sure about is those last formula, reaching to the 0% as the tax rate.